A helicopter tactile accedence warning system includes a control stick and a tactile warning device attached to the control stick. A computer or micro processor and a keyboard for entering a safe temperature profile are also provided as well as a thermocouple for measuring the turbine output temperature. The computer compares the actual temperature versus the safe temperature profile and generates a signal to activate the tactile warning device when the actual temperature falls outside of the safe temperature profile to warn a pilot to abort the start. The tactile warning device is also activated during flight operations when an over stress condition occurs to thereby warn the pilot to take corrective action. In addition, the tactile warning may be activated at a first frequency as an early warning and then at a second frequency as an indication of imminent danger.

Patent
   7262712
Priority
Apr 12 2004
Filed
Apr 12 2004
Issued
Aug 28 2007
Expiry
Jul 02 2024
Extension
81 days
Assg.orig
Entity
Large
12
27
all paid
1. A helicopter turbine engine over stress warning system comprising:
a helicopter;
a helicopter turbine engine mounted in said helicopter;
a collective and a tactile warning device including a collective shaker operatively connected to said collective;
data storage means and means for inputting a safe turbine output temperature profile for startup of the helicopter turbine engine and other safe operating parameters during flight of the helicopter;
means for measuring actual turbine output temperature during startup of the turbine engine and for detecting actual turbine output temperatures and other actual parameters during flight of the helicopter;
means to activate said tactile warning device when the actual turbine output temperature during startup falls outside of the safe turbine output temperature profile during startup and when the safe turbine output temperature or other safe operating parameters are exceeded during flight operations to thereby warn a pilot to take corrective action;
means for increasing the magnitude of the tactile warning when the turbine output temperature reaches its maximum operating temperature;
means for determining an impending dangerous condition associated with the other safe operating parameters; and
means for increasing the frequency of the tactile warning in response to the impending dangerous condition when the impending dangerous condition is imminent.

This invention relates to an exceedance or over stress warning system for helicopters and more particularly to a tactile warning system for avoiding “hot-starts” and other unsafe operating conditions.

Helicopters of the type having turbine engines typically include turbine outlet temperature sensors and/or monitors to avoid “hot-starts”. It is well recognized that during the first few seconds of a start, the turbine outlet temperature will accelerate at a fairly rapid rate and should be closely monitored. For example, with respect to one type of engine, a pilot should abort the start if either a 927° C. maximum or 810° C. to 927° C. maximum ten second transient limitation is about to be exceeded.

A method for correcting a “hot-start” condition is disclosed in a U.S. patent of Morris et al. U.S. Pat. No. 5,101,619. As disclosed therein a method for correcting a “hot-start” condition in a gas turbine engine without requiring a complete shutdown and re-initiation of the startup sequence, includes temporarily interrupting the flow of fuel to the engine for a brief period of time following detection of an impending “hot-start” condition.

A further approach to avoid “hot-starts” is disclosed in a U.S. Pat. No. 6,357,219 of Dudd, Jr. et al. As disclosed therein, a turbine engine fuel delivery system has, a fuel bypass for diverting fuel exiting a fuel control away from the engine and back to the fuel pump to maintain a relatively constant pressure differential across the fuel control. A separate controllable flow fuel bypass is provided for selectively diverting fuel exiting the fuel control away from the engine and back to the fuel pump to decrease the rate of fuel flow to the engine and correct an over temperature condition. The fuel delivery system also includes an arrangement for enabling the controllable fuel bypass during engine startup and disabling the controllable fuel bypass when the engine reaches normal idle speed.

Pilot warning systems which provide a tactile warning to the pilot during flight operations are also known. For example, my earlier patent of Greene et al. U.S. Pat. No. 6,002,349 discloses a helicopter anti-torque limit warning device. As disclosed therein, the pilot warning system acts on foot pedals which are operatively connected to the controllable force mechanism. The pedal movement controls the amount of force exerted by the controllable force mechanism on the tail boom to control the orientation of the helicopter about the yaw axis. A position sensing device senses the location of at least one of the foot pedals between its first and second position, and a warning indicator operatively connected to the position sensing device provides a warning to the pilot when the sensed foot pedal reaches a predetermined distance from one of the first and second positions. The warning indicator provides a tactile warning such as vibration or shaking of the respective foot pedal to provide an unmistakable warning to the pilot that the foot pedal has reached a predetermined position near its maximum travel position.

Notwithstanding the above, it is presently believed that there is a present need and a large potential commercial market for an improved over stress warning system for avoiding “hot-starts” in accordance with the present invention. There should be a commercial market for such systems that provide an early warning to abort a start and thereby avoid serious damage to a turbine engine.

In addition, systems in accordance with the present invention provide an unmistakable tactile warning to avoid “hot-starts”. Further, systems in accordance with a preferred embodiment of the invention also include tactile warning means for avoiding over stressed conditions such as output temperature, torque and engine speed during flight operations. Such systems include a single multi-function tactile warning device for warning a pilot of dangerous conditions.

In essence, the present invention contemplates a “hot-start” avoidance system for a helicopter of the type having a turbine engine. The system includes a collective and a tactile warning device operatively connected to the collective. The system also includes a data storage means such as a micro processor and an input device such as a keyboard for entering or inputting a safe temperature profile for the startup of a turbine engine. Means such as a thermocouple for measuring the actual turbine output temperature during the startup of a helicopter turbine engine are also provided. The system also includes means for activating the tactile warning device such as an electrical signal when the actual engine temperature during startup falls outside of a safe temperature profile. In one embodiment of the invention, an actual temperature profile is plotted by the micro processor and if a preselected profile is exceeded a warning will be given to the pilot to abort the startup of a turbine engine.

In a preferred embodiment of the invention an over stress warning system includes a “hot-start” avoidance system as described above. In addition, the system in accordance with the preferred embodiment of the invention includes means for activating the tactile warning system during flight operations when an over stress condition such as excessive torque, excessive temperature or engine speed are encountered. In this way, a pilot is warned to take corrective action before serious consequences are encountered.

In a modification of the preferred embodiment of the invention, the tactile warning system during flight operations is provided at a first frequency or perhaps a first amplitude at a first preselected level, as for example, a first critical parameter or dangerous condition is approached. Then, the frequency or amplitude is increased when a second preselected level or a critical parameter is exceeded.

The invention will now be described in connection with the accompanying drawings wherein like reference numbers have been used to describe like parts.

FIG. 1 is a side elevational view which shows a helicopter having an over-stress warning system in accordance with the present invention;

FIG. 2 is a schematic illustration of a helicopter turbine engine for use in practicing the present invention;

FIG. 3 is a schematic illustration of a helicopter collective having a tactile warning device attached thereto;

FIG. 4 is a block diagram which illustrates one embodiment of the invention;

FIG. 5 is a block diagram which illustrates another embodiment of the invention; and

FIG. 6 is a schematic illustration of a normal temperature profile during a safe startup of a helicopter turbine engine and a temperature profile for a “hot-start.

In FIG. 1, a helicopter 20 having a turbine engine 22 mounted therein and an over stress warning system is shown. As shown in FIG. 1, the over stress warning system includes a collective 24 and a tactile warning device 26 attached thereto. A conventional sensor 52 (FIG. 2) such as a thermocouple is provided for measuring the turbine outlet temperature of a helicopter turbine engine. The sensor 52 is connected to a micro processor 34. The micro processor is connected to a tactile warning device 26 such as a stick shaker which is attached to the helicopter collective 24.

FIG. 2 illustrates a turbine engine 22 of the type typically used for powering helicopters. As shown, the engine also includes a turbine outlet temperature sensor 52 which may be of any conventional design. Air is supplied to the turbine engine 22 through an inlet duct 40 and is compressed in a compressor section 41. Fuel is supplied to the combustion chamber 42 which extends peripherally around the engine. The expanded gasses are supplied to a turbine portion 43 which drives the compressor 41 and then to power the turbine 45 which drives an output shaft 44 to power the helicopter through a suitable gear train 47. A torque takeoff 48 of conventional design is provided for measuring actual torque during flight operations. A tachometer 49 is also provided for indicating engine speed. In addition, a temperature sensor 52 or thermocouple is provided for sensing the turbine output temperatures.

FIG. 3 illustrates a shaker 24 which is attached to the collector 26. In this type of installation, the shaker 24 is attached to a leaf spring 29 which in turn is attached at one end to a clamp 31. It should be recognized that the shaker 24 may provide a constant frequency or amplitude of vibration once it has been actuated or the frequency and/or amplitude of the vibration may increase as the turbine engine output temperature reaches its maximum operating temperature. The increase may either be continuously or may be in discreet steps reaching a maximum at the point for aborting the start.

FIG. 4 illustrates a method for avoiding “hot-starts” in accordance with one embodiment of the invention. In conventional practice, the turbine outlet temperature is monitored to avoid a “hot-start” which could seriously damage an engine. For example, a startup procedure for one specific engine is aborted if either the 927° C. maximum or the 810° C. to 927° C. maximum ten second transient limitation is about to be exceeded. Under such circumstances, a pilot depresses the engine idle release button, closes the throttle and continues to motor the starter until the turbine outlet temperature falls below 810° C.

In accordance with the present invention, a start 53 is initiated as provided in an FAA approved procedure. However, before initiating a startup procedure, a tactile device is attached to the collective and a data storage device is provided. Then in step 41 a safe temperature, safe temperature profile and critical conditions are inputted. A temperature profile may be inputted so that immediate action can be taken as soon as the actual temperature falls outside of the profile. It is also believed that the use of a temperature profile may be a more effective parameter which allows remedial action to be implemented earlier as the actual temperature approaches a dangerous condition.

After completing the FAA mandated pre-start check list, the engine starter motor is engaged in step 55, the fuel rate set in step 56 and ignition of the fuel in step 57. In step 58 the turbine outlet temperature is sensed and in step 59 the actual temperature is compared to the safe starting temperature or safe temperature profile. Then if the actual temperature does not exceed the safe temperature or fall outside of the temperature profile, the turbine engine is started as illustrated by step 60. However, if the actual temperature is greater then the safe temperature or falls outside of the temperature profile, a tactile warning is given in step 73 and the start is aborted in step 75. After aborting the start, the engine is allowed to cool. Then the engine start procedure is begun again in step 55 and a restart procedure is initiated.

After completing a start, actual conditions are sensed in step 77 and monitored in step 79. Then in step 81 the actual conditions are compared to the critical parameters and as long as the actual conditions do not approach the critical parameters, the actual conditions continued to be monitored as indicated by step 79. As contemplated by this embodiment of the invention, the input of the critical parameters includes the actual critical parameters including turbine output temperature during flight which require immediate action by the pilot. As well as a second level of parameters which are slightly less then the critical parameters are also provided. Then when the actual temperature or other actual parameter approach the critical parameters or critical temperature i.e. approximately equal to the critical parameters in step 81, the tactile warning device is acted at a first or relatively low frequency or amplitude in step 83.

The first level of warning is an indication to the pilot that he is approaching the critical parameters and should seriously consider taking corrective action. However, if the pilot continues to fly due to an emergency condition or the like without taking corrective action as indicated by step 85, the actual temperature and actual parameter are continuously compared until they exceed a second level or critical parameter as indicated by step 87. At this point the frequency of the tactile warning is increased in step 89 to warn the pilot to immediately take corrective action in step 91.

The increase in frequency may be accomplished by any conventional means as will be well understood by a person of ordinary skill in the art. For example, it may be accomplished in a similar manner to that disclosed in my earlier U.S. Pat. No. 6,002,348 which is included herein in its entirety be reference. Similarly, the frequency can be continuously increased as a dangerous condition is approached.

A further embodiment of the invention is illustrated in FIG. 5 wherein means for starting a helicopter turbine engine is provided as indicated by the number 54. Also provided are a collective and a tactile device 58 attached to the collective for providing a tactile signal when a critical parameter is about to be exceeded. The device also includes data storage means 60 such as a computer and input means 62 such as a keyboard for inputting the critical parameters into the data storage means 60. Means for starting the engine such as an engine crank 64 are used to start the engine while a fuel regulator 66 regulates the amount of fuel being provided to the turbine engine. Means for ignition 68 are used to ignite the fuel while a turbine outlet temperature sensor 70 is used to indicate the turbine output temperature. Comparater means 72 such as a computer compares the actual temperature from the temperature output temperature 70 with the safe temperature. Then, when the actual temperature exceeds the safe temperature the tactile actuator is actuated as indicated by the box 74. A kill switch 76 is provided so that the pilot can abort the start under such conditions. However, if the comparator 72 indicates that the actual temperature does not exceed the safe temperature the engine is started and the power controlled by a power control means 80. After the start of the engine and regulation of the power, the actual conditions of the engine are monitored by monitoring means 82 until such time that an actual condition exceeds a critical conditions. When an actual condition exceeds a critical condition, the tactile device is activated as indicated by 84 and corrective action is taken by the pilot as indicated by 86.

FIG. 6 is a schematic illustration of a temperature profile i.e., temperature versus time for a normal startup versus a temperature profile for a “hot-start”. For example, the temperature profile shown for a normal start up has a slope of about 30° C./second while a “hot-start” is shown with a slope of about 90° C./second.

While the invention has been described in connection with its accompanying drawings, changes and modifications may be made therein without departing from the scope of the appended claims.

Greene, Randall A.

Patent Priority Assignee Title
10474237, Jul 25 2017 Rolls-Royce Corporation Haptic feedback for rotary wing aircraft
10802482, Feb 27 2017 BELL HELICOPTER RHODE ISLAND INC ; Textron Innovations Inc Reverse tactile cue for rotorcraft rotor overspeed protection
11599111, Feb 27 2017 Textron Innovations Inc. Reverse tactile cue for rotorcraft rotor overspeed protection
8552847, May 01 2012 RACING INCIDENT PTY LTD ; SPEADTECH LIMITED Tactile based performance enhancement system
8626363, Feb 08 2007 BELL HELICOPTER TEXTRON INC Aircraft feathering, flapping and rotor loads indicator
8730065, Mar 22 2012 Lockheed Martin Corporation System and method for tactile presentation of information
8827207, May 03 2011 GOODRICH CORPORATION Ice protection system
8941476, May 01 2012 RACING INCIDENT PTY LTD ; SPEADTECH LIMITED Tactile based performance enhancement system
9327703, May 01 2012 RACING INCIDENT PTY LTD ; SPEADTECH LIMITED Tactile based performance enhancement system
9580186, Aug 28 2015 Safe Flight Instrument, LLC Helicopter tactile stall warning
9734678, May 01 2012 RACING INCIDENT PTY LTD ; SPEADTECH LIMITED Tactile based performance enhancement system
9868513, May 28 2014 Airbus Helicopters Device for warning a rotorcraft pilot by means of tactile signals and making use of a trim actuator connected to a flight control member
Patent Priority Assignee Title
2819838,
3145915,
3775745,
3799695,
4114442, Sep 03 1976 AVICON CORPORATION A CORP OF WY Temperature monitoring system
4115755, Jun 11 1976 United Technologies Corporation Aerodynamic surface load sensing
4420808, Apr 01 1980 United Technologies Corporation Multi-axis force stick, self-trimmed aircraft flight control system
4575803, Dec 30 1981 SEMCO INSTRUMENTS, INC , A CORP OF DELAWARE Engine monitor and recorder
4619110, Jul 13 1983 Helicopter engine warning or control system
4787053, Dec 30 1981 Semco Instruments, Inc. Comprehensive engine monitor and recorder
4908618, Dec 27 1988 The Boeing Company Abnormal start advisory system (ASAS) for aircraft engines
5101619, Feb 20 1990 UNITED TECHNOLOGIES CORPORATION, A CORP OF DE Method for correcting a hot start condition
5463873, Dec 06 1993 ARMSTRONG INTERNATIONAL, INC Method and apparatus for evaporative cooling of air leading to a gas turbine engine
5479350, Aug 23 1993 B & D INSTRUMENTS & AVIONICS, INC Exhaust gas temperature indicator for a gas turbine engine
5552711, Nov 10 1994 Turbine engine imminent failure monitor
5930990, May 14 1996 The Dow Chemical Company Method and apparatus for achieving power augmentation in gas turbines via wet compression
5986582, Jun 24 1998 Safe Flight Instrument Corporation Helicopter rotor/engine warning system
6002348, May 13 1998 Safe Flight Instrument Corporation Pilot's aid for detecting power lines
6002349, Aug 14 1998 Safe Flight Instrument Corporation Helicopter anti-torque limit warning device
6216443, Dec 28 1995 MITSUBISHI HITACHI POWER SYSTEMS, LTD Gas turbine, combined cycle plant and compressor
6260350, Jun 30 1997 Hitachi, LTD Gas turbine
6321526, Feb 19 1998 Mitsubishi Heavy Industries, Ltd. Gas turbine starting control system
6378285, Jan 22 1999 ANSALDO ENERGIA IP UK LIMITED Method for rapid startup and increase in output of a gas turbine plant
6422023, Dec 11 1998 AlliedSignal Inc. Turbine engine control with electronic and pneumatic governors
6772085, Dec 20 1999 Battelle Energy Alliance, LLC Device for self-verifying temperature measurement and control
20030094539,
WO2003081554,
///
Executed onAssignorAssigneeConveyanceFrameReelDoc
Apr 05 2004GREENE, RANDALL A Safe Flight Instrument CorporationASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS 0152050591 pdf
Apr 12 2004Safe Flight Instrument Corporation(assignment on the face of the patent)
Jan 28 2021Safe Flight Instrument, LLCFIRST EAGLE PRIVATE CREDIT, LLC F K A NEWSTAR FINANCIAL, INC SECURITY INTEREST SEE DOCUMENT FOR DETAILS 0552310691 pdf
Date Maintenance Fee Events
Jan 26 2011M2551: Payment of Maintenance Fee, 4th Yr, Small Entity.
Nov 28 2011ASPN: Payor Number Assigned.
Feb 11 2015M2552: Payment of Maintenance Fee, 8th Yr, Small Entity.
Feb 14 2019M2553: Payment of Maintenance Fee, 12th Yr, Small Entity.
Feb 25 2021BIG: Entity status set to Undiscounted (note the period is included in the code).


Date Maintenance Schedule
Aug 28 20104 years fee payment window open
Feb 28 20116 months grace period start (w surcharge)
Aug 28 2011patent expiry (for year 4)
Aug 28 20132 years to revive unintentionally abandoned end. (for year 4)
Aug 28 20148 years fee payment window open
Feb 28 20156 months grace period start (w surcharge)
Aug 28 2015patent expiry (for year 8)
Aug 28 20172 years to revive unintentionally abandoned end. (for year 8)
Aug 28 201812 years fee payment window open
Feb 28 20196 months grace period start (w surcharge)
Aug 28 2019patent expiry (for year 12)
Aug 28 20212 years to revive unintentionally abandoned end. (for year 12)